1. DNA, Genes, Chromosomes Chapter 6 & 9 The structure and function of Genes and Chromosomes Biology Fall 2012

2. Bell Ringer  What is the function of DNA?

3. Objectives  Big Picture:  Differentiate between a gene, a DNA molecule, a chromosome  Today:  Describe the location of a gene  Describe the function of a gene  Describe the structure of a chromosome  Describe the function of a chromosome

4. Chromosomes  ________________________: consists of DNA tightly coiled around _____________________, compacted form of DNA  DNA and proteins become ___________________ when in chromosome form  Function: carry portions of ______________________ information  ________________________: mass of genetic material composed of DNA and proteins  Will condense to form ____________________________

6. Chromosomes  _________________: the 2 exact copies of DNA that make up each of the chromosomes  ______________________: the point where two chromatids of a chromosomes are attached gene

7. Genes  Genes: _________________ of ______ that codes for a ____________________ or ___________ molecule  Single molecule of DNA has thousands of genes lined up like train cars

8. What is the point?  In Eukaryotic cell reproduction:  2 chromatids get ______________ during cell division and placed into each new ____________  Ensures that each new cells will have the same ______________ information as the original cell

9. Chromosome Number and Structure  ______________________ Cell: body cell, any cell other than sperm or egg  Has ____________________________ different chromosomes  Total of ________ chromosomes  23 chromosomes differ in size, shape and set of genes

10. Chromosome Number and Structure  _____________________ : are an organism’s reproductive cells  Sperm or eggs  Has _______________________ different chromosomes  Total of __________ chromosomes  1 egg + 1 sperm = ______ chromosomes

11. Sets of Chromosomes ________________________ chromosomes : chromosomes that are similar in size, shape, and genetic contents Each of 23 pairs of chromosomes consists of ____ homologous chromosomes Each _____________________ in a pair of homologous chromosomes comes from one of the two _________________

12. Sets of Chromosomes _________________: contains 2 sets of chromosomes, somatic cells  _______ = (23 x 2) = _____ ________________: contains 1 set of chromosomes, gamete cells  _____ = _____  Each organism has characteristic number of chromosomes

13. Activity Time!  Design a chromosome of your own.  Label and colour:  Chromosome  Centromere  Chromatids  2 Gene regions